1. Field of the Invention
This invention relates to surgical stapling apparatus, and more particularly to a surgical stapler for mechanically effecting a plurality of lines of stitching staples in body tissue.
2. Background of Related Art
In some surgical operations it is necessary to adjoin two hollow body organs alongside each other, generally with their longitudinal axes parallel to each other, and to effect a longitudinal cut through the contacting circumferential walls of the two organs so that the two organs constitute a single hollow chamber along the length of the cut. Correspondingly, the circumferential portions of the two adjoining organs on each lateral side of the cut must be sutured by at least one line of "stitches" in order to maintain the integrity of the union.
Instruments for this purpose can comprise two elongated fingers which are respectively insertable into each organ from an open end thereof, the two fingers thereby having between them the two adjoining walls of the organs. Typically, one of the fingers carries a disposable cartridge housing a plurality of staples arranged in at least two lateral rows while the other finger comprises an anvil for curling the staple legs into hook form upon their being driven against the anvil. The stapling operation is effected by a pusher which travels longitudinally along the cartridge carrying finger extending into one organ, with the pusher acting upon the staples to place rows of staples in body tissue. Immediately behind the pusher and laterally positioned between the staple rows is a knife which severs the facing adjoining walls of the two organs to thereby longitudinally open the two organs to each other between the rows of staples.
One such instrument is disclosed in Bobrov et al. (U.S. Pat. No. 3,079,606). The instrument disclosed therein comprises an apparatus for simultaneously making a longitudinal incision and applying a row of staples on both sides of the incision. A further improvement is disclosed in Green (U.S. Pat. No. 3,490,675).
A later development disclosed in Green (U.S. Pat. No. 3,499,591) applies a double row of staples on each side of the incision. This is accomplished by a cartridge assembly wherein a cam member moves within a guide path between two sets of staggered staple carrying grooves. Staple drive members located within the grooves each have two staple pusher plates, and sloping surfaces disposed within the guide path so as to be contacted by the longitudinally moving cam and be driven along the groove to effect ejection of two staples.
These above-mentioned instruments comprise upper and lower frames which must be assembled before use, and disassembled after use. Such instruments have been used successfully in surgical operations requiring the placement of gastrointestinal anastamosis, but they require the surgeon to have direct manual access to the operation site.
However, in laparoscopic procedures surgery is performed through a small incision, and in endoscopic procedures surgery is performed through narrow endoscopic tubes inserted through small entrance wounds in the skin. Up to now there have been no instruments for placing lateral staple lines in laparoscopic or endoscopic procedures. Nor has there been any instrument suitable for placing lateral lines of staples and cutting tissue therebetween in laparoscopic or endoscopic procedures.
Because endoscopic procedures are more common than laparoscopic procedures, the present invention shall be discussed in terms of endoscopic procedures and apparatus. However, use herein of terms such as "endoscopic", "endoscopically" and "endoscopic portion", among others, should not be construed to limit the present invention to a stapling and cutting apparatus for use only in conjunction with an endoscopic tube. To the contrary, it is believed the present invention may find use in any procedure where access is limited to a small incision, including but not limited to laparoscopic procedures. Also, as used herein the terms "fasteners" and "staples" shall be treated equivalently. Unless otherwise stated, the term "cartridge assembly" shall include at least the cartridge itself and staples or fasteners and staple drive members disposed therein.